JP2007324898A

JP2007324898A - Multi-optical-axis photoelectric sensor, its phototransmitter, and its photoreceiver

Info

Publication number: JP2007324898A
Application number: JP2006152487A
Authority: JP
Inventors: Hironori Nagai; 宏昇永井
Original assignee: Sunx Ltd
Current assignee: Panasonic Industrial Devices SUNX Co Ltd
Priority date: 2006-05-31
Filing date: 2006-05-31
Publication date: 2007-12-13

Abstract

<P>PROBLEM TO BE SOLVED: To provide a configuration capable of effectively suppressing trouble due to the difference of power on timings of a phototransmitter and a photoreceiver. <P>SOLUTION: The photoreceiver 30 includes an external output terminal to which an A contact switch is connected. A relay unit includes a B contact switch for outputting a normal operation signal corresponding to a detection signal when the A contact switch is normally operated in response to the detection signal. An abnormal detection terminal is connected to the B contact switch. When a photoreceiver side CPU determines an abnormality, a display unit performs announcement. The auxiliary output terminal of the phototransmitter 20 allows a signal treated as the normal operation signal in determining the abnormality to correspond to the detection signal, and outputs the signal to the abnormality detection terminal in a state where connection is electrically performed to the abnormal detection terminal. Moreover, the photoreceiver 30 includes a permitting means for permitting the abnormal determination when the start of the phototransmitter 20 is confirmed when the power source is supplied. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

本発明は、多光軸光電センサ、多光軸光電センサの投光器、多光軸光電センサの受光器に関する。 The present invention relates to a multi-optical axis photoelectric sensor, a multi-optical axis photoelectric sensor projector, and a multi-optical axis photoelectric sensor receiver.

従来より、複数の投光素子が備えられた投光器と各投光素子に対応して複数の受光素子が備えられた受光器とが対向して配置されてなる多光軸光電センサが提供されている。特許文献１の例に代表されるこの種の多光軸光電センサは、投光器に備えられた投光素子が所定の投光タイミングにて順次投光される投光スキャン動作を所定周期で繰り返し行うとともに、各投光素子と対応する受光素子からの受光信号に基づいて、検出エリア内への物体侵入が検出されるようになっている。
特開２００３−１３３９３３公報 Conventionally, a multi-optical axis photoelectric sensor is provided in which a light projector provided with a plurality of light projecting elements and a light receiver provided with a plurality of light receiving elements corresponding to each light projecting element are arranged to face each other. Yes. This type of multi-optical axis photoelectric sensor represented by the example of Patent Document 1 repeatedly performs a light projection scan operation in which light projection elements provided in a light projector are sequentially projected at a predetermined light projection timing at a predetermined cycle. At the same time, the intrusion of the object into the detection area is detected based on the light reception signal from the light receiving element corresponding to each light projecting element.
JP 2003-133933 A

上記のような多光軸光電センサでは、受光状態に基づいて得られた検出信号を外部に出力し、例えば外部に設けられた外部制御機器にて利用する方法が用いられている。 In the multi-optical axis photoelectric sensor as described above, a method is used in which a detection signal obtained based on the light receiving state is output to the outside and used in, for example, an external control device provided outside.

このように外部制御機器に検出信号を出力する場合、受光器から出力される信号を直接外部機器に入力させるのではなく、半導体リレーなどのスイッチング手段を介在させ、そのスイッチング手段を介した検出信号を外部制御機器に入力させるようにすれば、ノイズ等に強い高精度な出力構成を実現できることとなる。 Thus, when outputting a detection signal to an external control device, the signal output from the light receiver is not directly input to the external device, but a switching means such as a semiconductor relay is interposed, and the detection signal is passed through the switching means. Can be input to an external control device, a highly accurate output configuration resistant to noise or the like can be realized.

一方、上記のように受光器と外部機器との間にスイッチング手段を介在させる場合、そのスイッチング手段が正常に作動しているか否かを検出できるようにすると、検出信号の信頼性がより一層高まる。具体的には、投受光動作中にスイッチング手段が正常動作に応じて出力する正常動作信号を受光器に設けられた異常検出端子にて取得できるようにし、その正常動作信号に基づいて受光器側でスイッチング手段が正常であるか否かを判断できるようにすると、高精度かつ異常検出可能な出力構成を複雑な構成を伴うことなく実現できることとなる。 On the other hand, when the switching means is interposed between the light receiver and the external device as described above, if the switching means can detect whether or not it is operating normally, the reliability of the detection signal is further increased. . Specifically, the normal operation signal output by the switching means according to the normal operation during the light projecting / receiving operation can be acquired at the abnormality detection terminal provided in the light receiver, and the light receiver side is based on the normal operation signal. If it is possible to determine whether or not the switching means is normal, an output configuration that can detect an abnormality with high accuracy can be realized without a complicated configuration.

他方、利用者によっては、スイッチング手段を介在させずに用いたい場合もあるため、そのような場合にも好適に対応できる構成が望ましい。その例としては、投受光動作中に正常動作信号として扱われる信号を、同期信号と対応させて出力する補助出力端子を投光器側に設けるようにすればよい。このようにすれば、補助出力端子を異常検出端子に接続するだけで、正常動作信号として扱われる信号が投受光動作中に異常検出端子に入力されるようになるため、スイッチング手段を介在させなくても異常とならなくなり、スイッチング手段を介在させない使用を容易に実現できるようになる。 On the other hand, depending on the user, there is a case where it is desired to use the switching means without any intervening means. Therefore, a configuration that can cope with such a case is desirable. As an example, an auxiliary output terminal that outputs a signal that is treated as a normal operation signal during the light projecting / receiving operation in association with the synchronization signal may be provided on the light projector side. In this way, only by connecting the auxiliary output terminal to the abnormality detection terminal, a signal treated as a normal operation signal is input to the abnormality detection terminal during the light projecting / receiving operation, so that no switching means is interposed. Even if it does not become abnormal, it becomes possible to easily realize the use without interposing the switching means.

しかしながら、受光器で正常動作信号を取得して異常判断を行う構成の場合、多光軸光電センサ全体として立ち上がっていない場合に不具合が生じてしまう。例えば、受光器を電源投入して立ち上げた場合において、他方の投光器では未だ電源投入されていない場合、受光器では異常監視が開始されるものの、投受光動作されるべきタイミングで投光器から投光動作がなされないため、スイッチング手段が動作することはなく、結果として投受光動作されるべきタイミングで正常動作信号が出力されないこととなる。従って、スイッチング手段に不具合がなくても受光器で異常判定されるという不具合が生じることとなる。 However, in the case of a configuration in which a normal operation signal is acquired by a light receiver and an abnormality is determined, a problem occurs when the multi-optical axis photoelectric sensor as a whole is not up. For example, when the receiver is turned on and started up, if the other projector is not turned on yet, the receiver will start monitoring the abnormality, but the projector will emit light at the timing at which light should be sent and received. Since the operation is not performed, the switching means does not operate, and as a result, the normal operation signal is not output at the timing when the light projecting / receiving operation is to be performed. Therefore, even if the switching means is not defective, there is a problem that an abnormality is determined by the light receiver.

本発明は上記のような事情に基づいて完成されたものであって、投光器と受光器の電源投入のずれに起因する不具合を効果的に抑えることのできる構成を提供することを目的とする。 The present invention has been completed based on the above situation, and an object of the present invention is to provide a configuration that can effectively suppress problems caused by a difference in power-on between the projector and the light receiver.

上記の目的を達成するための手段として、請求項１の発明は、多光軸光電センサにおいて、
複数の投光素子を備えた投光器と、
各投光素子とそれぞれ光軸を構成するように配される複数の受光素子を備えた受光器と、
前記投光器と前記受光器とを接続する同期線と、
当該同期線を介して前記受光器から前記投光器へ送信される同期信号を生成する同期信号生成手段と、
各投光素子の投光タイミングを前記同期線を介して送信された前記同期信号に基づいて制御する投光制御手段と、
前記複数の受光素子を、前記同期信号に基づき各受光素子と対向して前記光軸を形成する前記投光素子の投光タイミングと同期させて受光動作させる受光制御手段と、
前記受光制御手段による各受光素子の受光状態に基づく検出信号を外部に出力する構成をなし、前記検出信号に対応したスイッチング動作を行うスイッチング手段が接続可能とされた外部出力端子と、
前記スイッチング手段が前記検出信号に応じて正常動作する場合に、前記検出信号と対応した前記正常動作信号を出力する正常動作信号出力手段が接続可能とされる異常検出端子と、
前記同期信号と、前記異常検出端子に入力される前記正常動作信号とに基づいて前記スイッチング手段の異常判断を行う異常判断手段と、
前記異常判断手段により異常判断された場合に報知を行う報知手段と、
前記異常検出端子と電気的に接続された場合に、前記異常判断手段により前記正常動作信号として扱われる信号を前記検出信号と対応させて前記異常検出端子に対して出力する補助出力端子と、
前記受光器の電源投入時に、前記投光器の起動を確認したことに基づいて前記異常判断手段による異常判断を許可する許可手段と、
を備えたことを特徴とする。 As means for achieving the above object, the invention of claim 1 is a multi-optical axis photoelectric sensor,
A projector having a plurality of projector elements;
A light receiver including a plurality of light receiving elements arranged to form an optical axis with each light projecting element;
A synchronization line connecting the projector and the light receiver;
Synchronization signal generating means for generating a synchronization signal transmitted from the light receiver to the projector via the synchronization line;
Projection control means for controlling the projection timing of each projection element based on the synchronization signal transmitted through the synchronization line;
A light receiving control means for performing a light receiving operation in synchronization with a light projecting timing of the light projecting element that forms the optical axis in opposition to each light receiving element based on the synchronization signal;
An external output terminal that is configured to output a detection signal based on a light receiving state of each light receiving element by the light receiving control means to the outside and to which a switching means that performs a switching operation corresponding to the detection signal can be connected;
An abnormality detection terminal to which a normal operation signal output means for outputting the normal operation signal corresponding to the detection signal is connectable when the switching means operates normally according to the detection signal;
An abnormality determination means for determining an abnormality of the switching means based on the synchronization signal and the normal operation signal input to the abnormality detection terminal;
An informing means for informing when an abnormality is determined by the abnormality determining means;
An auxiliary output terminal that, when electrically connected to the abnormality detection terminal, outputs a signal treated as the normal operation signal by the abnormality determination means to the abnormality detection terminal in association with the detection signal;
Permission means for permitting the abnormality determination by the abnormality determination means based on confirming the activation of the projector at the time of turning on the light receiver;
It is provided with.

請求項２の発明は、請求項１に記載の多光軸光電センサにおいて、
前記補助出力端子は、前記投光器の電源投入された場合に、前記検出信号に連動したオンオフ信号を出力することを特徴とする。 The invention of claim 2 is the multi-optical axis photoelectric sensor according to claim 1,
The auxiliary output terminal outputs an on / off signal linked to the detection signal when the projector is powered on.

請求項３の発明は、請求項１又は請求項２に記載の多光軸光電センサにおいて、
前記停止手段は、予め設定される所定の前記投光手段からの光を対応する各受光手段で受光したか否かに基づいて前記投光器の起動を確認することを特徴とする。 The invention of claim 3 is the multi-optical axis photoelectric sensor according to claim 1 or 2,
The stop means confirms the activation of the projector based on whether or not each of the corresponding light receiving means has received light from a predetermined preset light projecting means.

請求項４の発明は、請求項３に記載の多光軸光電センサにおいて、
前記停止手段は、全部の前記投光手段からの光を対応する前記各受光手段で受光したか否かに基づいて前記投光器の起動を確認することを特徴とする。 The invention of claim 4 is the multi-optical axis photoelectric sensor according to claim 3,
The stop means confirms the activation of the projector based on whether or not the light from all the light projecting means is received by the corresponding light receiving means.

請求項５の発明は、請求項３又は請求項４に記載の多光軸光電センサにおいて、
前記停止手段は、予め設定される１又は複数の前記投光手段からの光を対応する前記各受光手段により予め設定される所定回数受光したか否かに基づいて前記投光器の起動を確認することを特徴とする。 Invention of Claim 5 is the multi-optical axis photoelectric sensor of Claim 3 or Claim 4,
The stop means confirms the start of the projector based on whether or not light from one or a plurality of the light projecting means set in advance has been received by the corresponding light receiving means for a predetermined number of times. It is characterized by.

請求項６の発明は、
同期信号を生成する同期信号生成手段を備えた受光器の受光素子とそれぞれ光軸を構成するように配される複数の投光素子を備え、各投光素子の投光タイミングを前記同期信号に基づいて制御する投光制御手段を有する投光器であって、
前記複数の受光素子を、前記同期信号に基づき各受光素子と対向して前記光軸を形成する前記投光素子の投光タイミングと同期させて受光動作させる受光制御手段と、前記受光制御手段による各受光素子の受光状態に基づく検出信号を外部に出力する構成をなし、前記検出信号に対応したスイッチング動作を行うスイッチング手段が接続可能とされた外部出力端子と、前記スイッチング手段が前記検出信号に応じて正常動作する場合に前記検出信号に対応した前記正常動作信号を出力する正常動作信号出力手段が接続可能とされる異常検出端子と、前記同期信号と、前記異常検出端子に入力される前記正常動作信号とに基づいて前記スイッチング手段の異常判断を行う異常判断手段と、前記異常判断手段により異常判断された場合に報知を行う報知手段と、前記受光器の電源投入時に、前記投光器の起動を確認したことに基づいて前記異常判断手段による異常判断を許可する許可手段と、を備えた前記受光器と同期線を介して接続される構成をなし、
前記異常検出端子と電気的に接続された場合に、前記異常判断手段により前記正常動作信号として扱われる信号を前記検出信号と対応させて前記異常検出端子に対して出力する補助出力端子を備えたことを特徴とする。 The invention of claim 6
A light receiving element of a light receiver provided with a synchronization signal generating means for generating a synchronization signal, and a plurality of light projecting elements arranged so as to constitute an optical axis, respectively, and the light projecting timing of each light projecting element to the synchronization signal A projector having a projector control means for controlling based on the projector;
A light receiving control means for causing the plurality of light receiving elements to receive light in synchronization with the light projecting timing of the light projecting elements that form the optical axis facing each light receiving element based on the synchronization signal; and An external output terminal configured to output a detection signal based on a light receiving state of each light receiving element to the outside, to which a switching unit that performs a switching operation corresponding to the detection signal can be connected, and the switching unit to the detection signal In response to the normal operation, the normal operation signal output means for outputting the normal operation signal corresponding to the detection signal is connectable to the abnormality detection terminal, the synchronization signal, and the abnormality detection terminal input to the abnormality detection terminal An abnormality determining means for determining an abnormality of the switching means based on a normal operation signal, and a notification when an abnormality is determined by the abnormality determining means. Connected via a synchronization line to the light receiver comprising a notification means and a permission means for permitting an abnormality determination by the abnormality determination means based on confirming the activation of the projector when the light receiver is turned on Configured
An auxiliary output terminal that outputs a signal that is treated as the normal operation signal by the abnormality determination means to the abnormality detection terminal in association with the detection signal when electrically connected to the abnormality detection terminal; It is characterized by that.

請求項７の発明は、
同期信号を生成する同期信号生成手段を備え、複数の投光素子と、各投光素子の投光タイミングを前記同期信号に基づいて制御する投光制御手段と、を備えた投光器と、同期線を介して接続される受光器であって、
各投光素子とそれぞれ光軸を構成するように配される複数の受光素子と、
前記同期信号に基づき、前記複数の受光素子を、各受光素子と対向して前記光軸を形成する前記投光素子の投光タイミングと同期させて受光動作させる受光制御手段と、
前記受光制御手段による各受光素子の受光状態に基づく検出信号を外部に出力する構成をなし、前記検出信号に対応したスイッチング動作を行うスイッチング手段が接続可能とされた外部出力端子と、
前記スイッチング手段が前記検出信号に応じて正常動作する場合に前記検出信号と対応した正常動作信号を出力する正常動作信号出力手段が接続可能とされる異常検出端子と、
前記同期信号と、前記異常検出端子に入力される前記正常動作信号とに基づいて前記スイッチング手段の異常判断を行う異常判断手段と、
前記異常判断手段により異常判断された場合に報知を行う報知手段と、
を備え、
前記異常検出端子が、前記異常判断手段により前記正常動作信号として扱われる信号を前記検出信号と対応させて出力するように前記投光器に設けられた補助出力端子と接続可能とされており、
さらに、前記受光器の電源投入時に、前記投光器の起動を確認したことに基づいて前記異常判断手段による異常判断を許可する許可手段を備えたことを特徴とする。 The invention of claim 7
A projector including a synchronization signal generating unit configured to generate a synchronization signal, a projector including a plurality of light projecting elements, and a light projecting control unit configured to control a light projecting timing of each light projecting element based on the synchronization signal; A receiver connected via
A plurality of light receiving elements arranged to form an optical axis with each light projecting element;
A light receiving control means for performing a light receiving operation in synchronization with a light projecting timing of the light projecting element that forms the optical axis in opposition to each of the light receiving elements based on the synchronization signal;
An external output terminal that is configured to output a detection signal based on a light receiving state of each light receiving element by the light receiving control means to the outside and to which a switching means that performs a switching operation corresponding to the detection signal can be connected;
An abnormality detection terminal to which a normal operation signal output means for outputting a normal operation signal corresponding to the detection signal when the switching means operates normally in response to the detection signal;
An abnormality determination means for determining an abnormality of the switching means based on the synchronization signal and the normal operation signal input to the abnormality detection terminal;
An informing means for informing when an abnormality is determined by the abnormality determining means;
With
The abnormality detection terminal is connectable to an auxiliary output terminal provided in the projector so as to output a signal treated as the normal operation signal by the abnormality determination means in association with the detection signal,
Furthermore, it is characterized by further comprising permission means for permitting abnormality determination by the abnormality determination means based on confirmation of activation of the light projector when the light receiver is turned on.

＜請求項１の発明＞
請求項１の発明によれば、投光器と受光器の電源投入のずれに起因する不具合を効果的に抑えることのできる構成となる。 <Invention of Claim 1>
According to invention of Claim 1, it becomes the structure which can suppress effectively the malfunction resulting from the shift | offset | difference of power activation of a light projector and a light receiver.

＜請求項２の発明＞
請求項２の発明によれば、正常動作信号として扱われる信号を簡易に生成できる好適例となる。 <Invention of Claim 2>
According to invention of Claim 2, it becomes a suitable example which can produce | generate the signal handled as a normal operation signal easily.

＜請求項３の発明＞
請求項３の構成によれば、特別な構成や複雑な構成を用いることなく投光器の電源投入を受光器側で確認できるようになる。 <Invention of Claim 3>
According to the configuration of the third aspect, it is possible to confirm the power-on of the projector on the light receiver side without using a special configuration or a complicated configuration.

＜請求項４の発明＞
請求項４の構成によれば、投光器の電源投入をより確実に確認できる好適例となる。 <Invention of Claim 4>
According to the structure of Claim 4, it becomes a suitable example which can confirm the power activation of a projector more reliably.

＜請求項５の発明＞
請求項５の構成によれば、投光器の電源投入をより確実に確認できる好適例となる。 <Invention of Claim 5>
According to the structure of Claim 5, it becomes a suitable example which can confirm the power activation of a projector more reliably.

＜請求項６の発明＞
請求項６の発明によれば、請求項１と同様の効果を奏する投光器となる。 <Invention of Claim 6>
According to invention of Claim 6, it becomes a projector which has an effect similar to Claim 1.

＜請求項７の発明＞
請求項７の発明によれば、請求項１と同様の効果を奏する受光器となる。 <Invention of Claim 7>
According to invention of Claim 7, it becomes a light receiver which has an effect similar to Claim 1.

＜実施形態１＞
本発明の実施形態１を図面を参照しつつ説明する。
本実施形態の多光軸光電センサ１０は、図１に示すように、投光器２０と受光器３０とを対向させた状態で構成され、例えば、４チャンネルの光軸Ｌ１〜Ｌ４を有する。投光器２０のうち受光器３０と対向する面には、各チャンネル毎に１個（計４個）の投光素子２１ａ〜２１ｄ（例えば、ＬＥＤ）が上下方向に一列に配列され、受光器３０のうち投光器２０と対向する面には投光素子２１ａ〜２１ｄと対をなす受光素子３１ａ〜３１ｄ（例えば、フォトダイオード）が同じく上下方向に配列されている。なお、多光軸光電センサ１０の下方には他の多光軸光電センサＡが近接して配置されている。 <Embodiment 1>
Embodiment 1 of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the multi-optical axis photoelectric sensor 10 of the present embodiment is configured with the projector 20 and the light receiver 30 facing each other, and has, for example, four-channel optical axes L1 to L4. On the surface of the light projector 20 facing the light receiver 30, one (total of four) light projecting elements 21 a to 21 d (for example, LEDs) are arranged in a line in the vertical direction for each channel. Among them, light receiving elements 31a to 31d (for example, photodiodes) that are paired with the light projecting elements 21a to 21d are similarly arranged in the vertical direction on the surface facing the projector 20. Note that another multi-optical axis photoelectric sensor A is disposed in the vicinity of the multi-optical axis photoelectric sensor 10.

本実施形態の多光軸光電センサ１０の電気的構成を図２に示す。
投光器２０と受光器３０は同期線４０を介して接続されている。投光器２０には投光素子２１ａ〜２１ｄを点灯させるための駆動回路２２ａ〜２２ｄが備えられ、各駆動回路２２ａ〜２２ｄはＡＮＤ回路２３ａ〜２３ｄからの信号を受けると投光素子２１ａ〜２１ｄに駆動電流を供給する。ＡＮＤ回路２３ａ〜２３ｄにはシフトレジスタ２４及び投光側ＣＰＵ２５からの出力信号が入力され、双方からの信号が入力されると駆動回路２２ａ〜２２ｄに信号を送出するようになっている。投光側ＣＰＵ２５は後述する受光器３０に備えられた受光側ＣＰＵ３５から同期線４０を介して同期信号Ｓｔを受けとり、この同期信号Ｓｔと同一の周期及び位相の信号Ｓｆをシフトレジスタ２４及びＡＮＤ回路２３ａ〜２３ｄに出力する。 FIG. 2 shows an electrical configuration of the multi-optical axis photoelectric sensor 10 of the present embodiment.
The projector 20 and the light receiver 30 are connected via a synchronization line 40. The projector 20 is provided with drive circuits 22a to 22d for turning on the light projecting elements 21a to 21d, and the drive circuits 22a to 22d are driven by the light projecting elements 21a to 21d when receiving signals from the AND circuits 23a to 23d. Supply current. Output signals from the shift register 24 and the light-projecting CPU 25 are input to the AND circuits 23a to 23d. When signals from both are input, signals are sent to the drive circuits 22a to 22d. The light emitting side CPU 25 receives a synchronization signal St from a light receiving side CPU 35 provided in the light receiver 30 described later via a synchronization line 40, and outputs a signal Sf having the same cycle and phase as the synchronization signal St to the shift register 24 and the AND circuit. It outputs to 23a-23d.

同期信号Ｓｔは所定周期のパルス信号であって（図３参照）、投光素子２１ａ〜２１ｄの点灯タイミングを決定するために受光側ＣＰＵ３５によって生成される。同期信号Ｓｔのスキャン周期（Ｔ１時間）内には４個のパルスが時間ｔａを空けて等間隔に発生し、４番目のパルスの後、休止期間ｔｂが設けられている。これにより、４個の投光素子２１ａ〜２１ｄが上から下へと順次点灯される投光スキャン動作が周期Ｔ１毎に繰り返し行なわれる。 The synchronization signal St is a pulse signal having a predetermined period (see FIG. 3), and is generated by the light receiving side CPU 35 in order to determine the lighting timing of the light projecting elements 21a to 21d. Within the scanning period (time T1) of the synchronization signal St, four pulses are generated at equal intervals with a time ta, and a pause period tb is provided after the fourth pulse. Thereby, the light projection scanning operation in which the four light projecting elements 21a to 21d are sequentially turned on from the top to the bottom is repeatedly performed every period T1.

一方、受光器３０には、受光素子３１ａ〜３１ｄからの受光信号を所定の増幅率で増幅する受光アンプ３２ａ〜３２ｄが各受光素子３１ａ〜３１ｄにそれぞれ備えられている。受光アンプ３２ａ〜３２ｄから出力される受光信号はアナログスイッチ３３ａ〜３３ｄを介し、共通の信号線にまとめられてコンパレータ３４に取り込まれる。この受光信号がコンパレータ３４に設定されている基準値以上であればハイレベル、基準値以下であるとロウレベルとなる入遮光検出信号Ｓｄが受光側ＣＰＵ３５に出力される。そして、受光側ＣＰＵ３５に入力された入遮光検出信号Ｓｄがハイレベルであればその受光素子３１ａ（〜３１ｄ）に光（投受光動作で受光した光又は干渉光）が入射したことが検出される一方、受光側ＣＰＵ３５に入力された信号がロウレベルであればその受光素子３１ａ〜３１ｄに光が入射しない（遮光されている）ことが検出される。 On the other hand, the light receiver 30 includes light receiving amplifiers 32a to 32d that amplify light reception signals from the light receiving elements 31a to 31d at a predetermined amplification rate, respectively. The light receiving signals output from the light receiving amplifiers 32a to 32d are collected into a common signal line and taken into the comparator 34 via the analog switches 33a to 33d. If this received light signal is equal to or higher than the reference value set in the comparator 34, an incoming light blocking detection signal Sd that is high level and lower than the reference value is output to the light receiving side CPU 35. Then, if the incoming light blocking detection signal Sd input to the light receiving side CPU 35 is at a high level, it is detected that light (light received by the light projecting / receiving operation or interference light) is incident on the light receiving element 31a (to 31d). On the other hand, if the signal input to the light receiving side CPU 35 is at a low level, it is detected that light is not incident (shielded) on the light receiving elements 31a to 31d.

受光側ＣＰＵ３５はシフトレジスタ３７に接続されており、このシフトレジスタ３７が上述の各アナログスイッチ３３ａ〜３３ｄに接続されている。受光側ＣＰＵ３５は、自身が生成する同期信号Ｓｔのパルスと周期及び位相が一致した（同期した）パルスＳｇを所定時間（間隔ta）ごとにシフトレジスタ３７に出力する構成をなしており、シフトレジスタ３７は、同期信号Ｓｔのパルスと周期及び位相を一致させて各アナログスイッチ３３ａ〜３３ｄに対して所定の順序で信号を出力する。これにより、投光素子２１ａ〜２１ｄのそれぞれの投光タイミングと同タイミングで対応する各アナログスイッチ３３ａ〜３３ｄが選択的にオン状態となり、投受光動作中の光軸に係る受光信号のみが選択的にコンパレータ３４に入力されるようになる。 The light receiving side CPU 35 is connected to a shift register 37, and this shift register 37 is connected to each of the analog switches 33a to 33d described above. The light receiving side CPU 35 is configured to output, to the shift register 37, a pulse Sg having the same period and phase (synchronized) with the pulse of the synchronization signal St generated by itself, every predetermined time (interval ta). 37 outputs a signal in a predetermined order to each of the analog switches 33a to 33d by matching the period and phase of the pulse of the synchronization signal St. As a result, the corresponding analog switches 33a to 33d are selectively turned on at the same timing as the light projecting timings of the light projecting elements 21a to 21d, and only the light receiving signals related to the optical axis during the light projecting / receiving operation are selectively selected. To the comparator 34.

上記のように、本実施形態に係る多光軸光電センサ１では、同期線４０を介して受光器３０と投光器２０が接続されており、受光器２０に設けられた受光器側ＣＰＵ３５は、受光器３０から投光器２０へ送信される同期信号Ｓｔを生成する機能を有している。本実施形態では、この受光器側ＣＰＵ３５が同期信号生成手段の一例に相当している。 As described above, in the multi-optical axis photoelectric sensor 1 according to the present embodiment, the light receiver 30 and the projector 20 are connected via the synchronization line 40, and the light receiver side CPU 35 provided in the light receiver 20 receives light. It has a function of generating a synchronization signal St transmitted from the projector 30 to the projector 20. In the present embodiment, the light receiver side CPU 35 corresponds to an example of a synchronization signal generating unit.

また、本実施形態では、上述のＡＮＤ回路２３ａ〜２３ｄ、シフトレジスタ２４、投光側ＣＰＵ２５は、各投光素子２１ａ〜２１ｄの投光タイミングを同期線４０を介して送信された同期信号Ｓｔに基づいて制御する投光制御手段に相当している。 In the present embodiment, the AND circuits 23 a to 23 d, the shift register 24, and the light-projecting side CPU 25 described above use the timing of projecting the light projecting elements 21 a to 21 d to the synchronization signal St transmitted via the synchronization line 40. This corresponds to a light projecting control means for controlling based on this.

また、受光側ＣＰＵ３５、シフトレジスタ３７、アナログスイッチ３３ａ〜３３ｄは、複数の受光素子３１ａ〜３１ｄを、同期信号Ｓｔに基づき各受光素子３１ａ〜３１ｄと対向して光軸を形成する投光素子２１ａ〜２１ｄの投光タイミングと同期させて受光動作させる受光制御手段に相当している。 Further, the light receiving side CPU 35, the shift register 37, and the analog switches 33a to 33d have a plurality of light receiving elements 31a to 31d facing each of the light receiving elements 31a to 31d based on the synchronization signal St to form an optical axis 21a. This corresponds to a light receiving control means for performing a light receiving operation in synchronization with the light projecting timing of ~ 21d.

さらに、受光器３０には、これらの受光制御手段による各受光素子３１ａ〜３１ｄの受光状態に基づく検出信号Ｓａを外部に出力する外部出力端子Ｐ１が設けられている。この外部出力端子Ｐ１は、検出信号Ｓａに対応したスイッチング動作を行うＡ接点スイッチＳＷ１（Ａ接点スイッチＳＷ１はスイッチング手段の一例に相当する）が接続可能とされるものであり、図２では、そのＡ接点スイッチＳＷ１が接続された様子を示している。Ａ接点スイッチＳＷ１は例えばバイポーラトランジスタやＭＯＳＦＥＴなどによって構成されるものであり、外部出力端子Ｐ１からのオン信号に応じてオンし、Ｐ１からオフ信号が出力された場合にオフする構成をなしている。 Furthermore, the light receiver 30 is provided with an external output terminal P1 for outputting a detection signal Sa based on the light receiving state of each of the light receiving elements 31a to 31d by these light receiving control means. The external output terminal P1 can be connected to an A-contact switch SW1 that performs a switching operation corresponding to the detection signal Sa (the A-contact switch SW1 corresponds to an example of a switching means). A state where the A contact switch SW1 is connected is shown. The A contact switch SW1 is composed of, for example, a bipolar transistor or a MOSFET, and is turned on in response to an on signal from the external output terminal P1 and turned off when an off signal is output from P1. .

Ａ接点スイッチＳＷ１が設けられたリレーユニット５０には、Ａ接点スイッチＳＷ１が検出信号Ｓａに応じて正常動作する場合に、検出信号Ｓａと対応した正常動作信号Ｓｃを出力するＢ接点スイッチＳＷ２が設けられている。具体的には、Ｂ接点スイッチＳＷ２は、Ａ接点スイッチＳＷ１からの出力信号Ｓｂを反転した反転信号を出力するものであり、正常動作信号出力手段の一例として機能している。この構成では、Ａ接点スイッチＳＷ１が変化しない限り正常動作信号Ｓｃが変化し内容になっており、例えば、検出信号Ｓａが出力されているにもかかわらずＡ接点スイッチＳＷ１がオンしない場合には、正常動作信号Ｓｃが出力せず、図４のように検出信号出力時にも正常動作信号がオフ状態（ハイレベル）で維持されることとなる。なお、ここでは、正常動作信号出力手段としてＢ接点スイッチＳＷ２を例示したが、スイッチング手段が正常に作動していることを示す信号が出力できる構成であればこの構成に限られない。例えば、本実施形態の構成では、検出信号ＳａがＡ接点スイッチＳＷ１及びＢ接点スイッチＳＷ２に共に入力され、当該信号Ｓａが両スイッチを駆動しているが、Ａ接点スイッチＳＷ１の出力信号（外部装置７０への出力信号）がＢ接点スイッチＳＷ２に入力され、Ａ接点スイッチＳＷ１からの出力があった場合にのみＢ接点スイッチＳＷ２がその反転信号を出力するような構成であってもよい。 The relay unit 50 provided with the A contact switch SW1 is provided with a B contact switch SW2 that outputs a normal operation signal Sc corresponding to the detection signal Sa when the A contact switch SW1 operates normally in response to the detection signal Sa. It has been. Specifically, the B contact switch SW2 outputs an inverted signal obtained by inverting the output signal Sb from the A contact switch SW1, and functions as an example of a normal operation signal output unit. In this configuration, unless the A contact switch SW1 changes, the normal operation signal Sc changes and becomes the content. For example, when the A contact switch SW1 does not turn on despite the detection signal Sa being output, The normal operation signal Sc is not output, and the normal operation signal is maintained in the off state (high level) even when the detection signal is output as shown in FIG. Here, the B contact switch SW2 is exemplified as the normal operation signal output means, but the present invention is not limited to this structure as long as it can output a signal indicating that the switching means is operating normally. For example, in the configuration of this embodiment, the detection signal Sa is input to both the A contact switch SW1 and the B contact switch SW2, and the signal Sa drives both switches, but the output signal of the A contact switch SW1 (external device) (The output signal to 70) is input to the B contact switch SW2, and the B contact switch SW2 outputs the inverted signal only when there is an output from the A contact switch SW1.

受光器３０には、Ｂ接点スイッチＳＷ２が接続可能とされた異常検出端子Ｐ２が設けられており、異常検出端子Ｐ２に入力される信号は、受光側ＣＰＵ３５に取り込まれるようになっている。なお、異常検出端子Ｐ２と受光側ＣＰＵ３５との間にＡ／Ｄ変換器を介在させてもよい。 The light receiver 30 is provided with an abnormality detection terminal P2 to which the B contact switch SW2 can be connected, and a signal inputted to the abnormality detection terminal P2 is taken into the light receiving side CPU 35. An A / D converter may be interposed between the abnormality detection terminal P2 and the light receiving side CPU 35.

受光側ＣＰＵ３５は、同期信号Ｓｔと、異常検出端子Ｐ２に入力される正常動作信号Ｓｃとに基づいてＡ接点スイッチＳＷ１の異常判断を行う機能を有している。なお、この受光側ＣＰＵ３５は異常判断手段の一例に相当する。具体的には、同期信号Ｓｔが出力されるスキャン周期Ｔ１内に正常動作信号Ｓｃが全く異常検出端子Ｐ２に入力されない場合（即ち、図４のようにスキャン周期Ｔ１において反転信号が入力されずスキャン周期Ｔ１に亘ってハイレベルが維持されている場合）、異常であると判断し、所定の報知動作（例えば、表示部３８における警告表示等）がなされるようになっている。なお、表示部３８及び受光側ＣＰＵ３７は、異常判断された場合に報知を行う報知手段の一例に相当する。 The light receiving side CPU 35 has a function of determining abnormality of the A contact switch SW1 based on the synchronization signal St and the normal operation signal Sc input to the abnormality detection terminal P2. The light receiving side CPU 35 corresponds to an example of an abnormality determination unit. Specifically, when the normal operation signal Sc is not input to the abnormality detection terminal P2 within the scan cycle T1 in which the synchronization signal St is output (that is, the inversion signal is not input and the scan is not performed in the scan cycle T1 as shown in FIG. 4). When the high level is maintained over the period T1), it is determined that there is an abnormality, and a predetermined notification operation (for example, a warning display on the display unit 38) is performed. The display unit 38 and the light receiving side CPU 37 correspond to an example of a notification unit that performs notification when an abnormality is determined.

一方、投光器２０には、補助出力端子Ｐ５が設けられている。この補助出力端子Ｐ５は、投光器２０が電源投入された場合に、検出信号Ｓａに連動した（対応した）オンオフ信号を出力するものである。具体的には、同期線４０を介して投光器２０に入力される同期信号Ｓｔを反転して補助出力端子Ｐ５から出力する反転出力手段が設けられており、この反転出力手段からの出力が補助出力端子Ｐ５から出力されることとなる。本実施形態では、同期信号Ｓｔを取得した投光側ＣＰＵ２５が同期信号Ｓｔとほぼ同タイミングで同期信号Ｓｔを反転した擬似正常動作信号Ｓｅを出力するようになっているが、投光器２０の端子Ｐ４に接続される反転回路を設け、この反転回路から端子Ｐ５に擬似正常動作信号Ｓｅを出力するようにしてもよい（この場合には、投光側ＣＰＵ２５から反転信号を出力しなくてもよい）。いずれにしてもこのような補助出力端子Ｐ５が設けられることで、図５のようなリレーユニット５０の非接続時に異常検出に基づく報知動作が行われないようにすることができる。即ち、図５のように補助出力端子Ｐ５が異常検出端子Ｐ２と電気的に接続された場合、この補助出力端子Ｐ５からは正常動作信号として扱われる擬似正常動作信号Ｓｅ（検出信号Ｓａを反転した信号）が検出信号Ｓａと対応して出力され、この擬似正常動作信号Ｓｅが異常検出端子Ｐ２に入力されることとなる。なお、このような補助出力端子Ｐ５が設けられていると、投光器２０の動作状態の確認にも利用できることとなる。 On the other hand, the projector 20 is provided with an auxiliary output terminal P5. The auxiliary output terminal P5 outputs an on / off signal linked to (corresponding to) the detection signal Sa when the projector 20 is turned on. Specifically, an inverting output means for inverting the synchronizing signal St input to the projector 20 via the synchronizing line 40 and outputting the inverted signal from the auxiliary output terminal P5 is provided, and the output from the inverting output means is the auxiliary output. It is output from the terminal P5. In the present embodiment, the projector-side CPU 25 that has acquired the synchronization signal St outputs the pseudo-normal operation signal Se obtained by inverting the synchronization signal St at almost the same timing as the synchronization signal St. However, the terminal P4 of the projector 20 And the pseudo normal operation signal Se may be output from the inversion circuit to the terminal P5 (in this case, the inversion signal may not be output from the light emitting side CPU 25). . In any case, by providing such an auxiliary output terminal P5, it is possible to prevent a notification operation based on abnormality detection from being performed when the relay unit 50 is not connected as shown in FIG. That is, when the auxiliary output terminal P5 is electrically connected to the abnormality detection terminal P2 as shown in FIG. 5, the pseudo output signal Se (detection signal Sa that is treated as a normal operation signal is inverted from the auxiliary output terminal P5. Signal) is output in correspondence with the detection signal Sa, and this pseudo-normal operation signal Se is input to the abnormality detection terminal P2. If such an auxiliary output terminal P5 is provided, it can also be used to check the operating state of the projector 20.

本実施形態に係る多光軸光電センサ１の投光器２０及び受光器３０は、例えば図６のような外観をなしており、複数の電線に各端子が設けられている。そしてリレーユニット５０を用いる場合には、外部出力端子Ｐ１及び異常検出端子Ｐ２に図２のようにリレーユニット５０を接続する。一方、リレーユニット５０を用いない場合には、異常検出端子Ｐ２と補助出力端子Ｐ５とを接続しさえすれば容易に対応できるため、いずれの場合も設定作業を容易に行うことができる。 The projector 20 and the light receiver 30 of the multi-optical axis photoelectric sensor 1 according to the present embodiment have, for example, an appearance as shown in FIG. 6, and each terminal is provided on a plurality of electric wires. When the relay unit 50 is used, the relay unit 50 is connected to the external output terminal P1 and the abnormality detection terminal P2 as shown in FIG. On the other hand, when the relay unit 50 is not used, it can be easily handled as long as the abnormality detection terminal P2 and the auxiliary output terminal P5 are connected. Therefore, the setting operation can be easily performed in either case.

次に、受光器３０における電源投入の際の処理の流れについて説明する。
図７は受光器３０が電源投入された際に行われる初期処理を例示するフローチャートである。なお、この初期処理が終了することを条件として実際の検出処理（上述した投受光動作に応じた検出信号Ｓａの出力処理や正常動作信号Ｓｃ或いは擬似正常動作信号Ｓｅに基づく異常判断処理）が実行されることとなる。なお、この処理は受光器３０に設けられた図示しない記憶手段（ＲＯＭ等）に記憶されたプログラムに従って受光側ＣＰＵ３５により実行される。 Next, the flow of processing when the light receiver 30 is turned on will be described.
FIG. 7 is a flowchart illustrating an initial process performed when the light receiver 30 is turned on. The actual detection process (output process of the detection signal Sa corresponding to the light projecting / receiving operation and the abnormality determination process based on the normal operation signal Sc or the pseudo normal operation signal Se) is executed on condition that the initial process is completed. Will be. This process is executed by the light receiving side CPU 35 according to a program stored in a storage means (ROM or the like) (not shown) provided in the light receiver 30.

当該処理が開始されると、光軸数の診断、アナログスイッチの診断、受光回路の診断などの各部品初期診断処理を行う（Ｓ１０）。なお、ここに示す例はあくまで一例であり、様々な部品の診断処理を行うことができることはいうまでもない。 When the processing is started, initial component diagnosis processing such as diagnosis of the number of optical axes, diagnosis of an analog switch, diagnosis of a light receiving circuit, and the like is performed (S10). In addition, the example shown here is an example to the last, and it cannot be overemphasized that the diagnostic process of various components can be performed.

Ｓ１０における各部品初期診断処理が終わると、Ｓ２０にて同期方式を判断する。即ち、当該受光器３０が線同期方式として用いられようとしているのか、或いは光同期方式として用いられようとしているのかを判断する。 When each component initial diagnosis process in S10 is completed, the synchronization method is determined in S20. That is, it is determined whether the light receiver 30 is to be used as a line synchronization method or an optical synchronization method.

具体的には、端子Ｐ３に同期線４０が接続されているか否かを判断し、接続されている場合には線同期方式が採用されたものとしてＳ２０にてＹに進む。一方、同期線４０が端子Ｐ３に接続されていない場合には光同期方式が採用されたものとしてＳ２０にてＮに進む。 Specifically, it is determined whether or not the synchronization line 40 is connected to the terminal P3. If it is connected, it is determined that the line synchronization method is adopted, and the process proceeds to Y in S20. On the other hand, if the synchronization line 40 is not connected to the terminal P3, the process proceeds to N in S20 assuming that the optical synchronization method is adopted.

なお、Ｓ２０にて光同期方式が採用された場合には、Ｓ６０にて光同期信号を取得するまで待機する。即ち、本実施形態では所定の光軸を構成する投光素子から光同期信号が出力されるようになっているため、受光器３０では、投光器２０に電源が投入され、かつ光同期信号を出力する投光素子と共に光軸を構成する受光素子に光同期信号が入力されるまで待機する。所定光軸の受光素子において光同期信号が取得できた場合には、投光器２０及び受光器３０が共に立ち上がったことが確認できたものとしてＳ６０にてＹに進み、当該処理を終了する。 When the optical synchronization method is adopted in S20, the process waits until an optical synchronization signal is acquired in S60. That is, in this embodiment, since the light synchronization signal is output from the light projecting elements that constitute the predetermined optical axis, the light receiver 30 supplies power to the light projector 20 and outputs the light synchronization signal. It waits until an optical synchronizing signal is input into the light receiving element which comprises an optical axis with the light projecting element to perform. If the optical synchronization signal can be acquired in the light receiving element having the predetermined optical axis, it is determined that both the projector 20 and the light receiver 30 have risen, and the process proceeds to Y in S60 to end the process.

一方、Ｓ２０にてＹに進む場合、Ｓ３０にて同期信号を出力する。同期信号は同期信号生成手段として構成される受光側ＣＰＵ３５にて生成され、同期線４０を介して出力される。 On the other hand, when the process proceeds to Y in S20, a synchronization signal is output in S30. The synchronization signal is generated by the light receiving side CPU 35 configured as a synchronization signal generation means, and is output via the synchronization line 40.

そして、Ｓ４０にて受光動作を行う。即ち、投光器２０に電源が投入されている場合には上述したように同期信号に応じて投光動作がなされるため、その投光動作に応じた受光動作をＳ４０にて行うこととなる。 In S40, a light receiving operation is performed. That is, when the projector 20 is powered on, a light projecting operation is performed in accordance with the synchronization signal as described above. Therefore, a light receiving operation corresponding to the light projecting operation is performed in S40.

そして、Ｓ５０にて全光軸入光が確認されたかを判断する。即ち、投光器２０に既に電源が投入されており、同期信号に応じた投光動作がなされている場合には、全ての光軸の受光素子において入光が確認できるはずなのでＳ５０にてそれを確認する。 Then, in S50, it is determined whether or not all optical axis incident light has been confirmed. That is, when the projector 20 is already turned on and the projection operation according to the synchronization signal is performed, the incident light should be confirmed in the light receiving elements of all the optical axes. To do.

Ｓ５０にて全ての光軸において入光が確認されない場合にはＳ５０にてＮに進み、Ｓ３０からＳ５０までの処理を繰り返す。全ての光軸で入光が確認される場合には電源投入が確認できたものとしてＳ５０にてＹに進み、当該処理を終了する。この初期処理が終了すると、上述した投受光動作に応じた検出信号Ｓａの出力処理や正常動作信号Ｓｃ或いは擬似正常動作信号Ｓｅに基づく異常判断処理が行われることとなる。 If no incident light is confirmed in all optical axes in S50, the process proceeds to N in S50, and the processes from S30 to S50 are repeated. If the incident light is confirmed on all the optical axes, it is determined that the power has been turned on, the process proceeds to Y in S50, and the process ends. When this initial process is completed, the output process of the detection signal Sa corresponding to the light projecting / receiving operation and the abnormality determination process based on the normal operation signal Sc or the pseudo normal operation signal Se are performed.

なお、本実施形態では、Ｓ３０〜Ｓ５０に示すように、線同期方式を採用した場合、受光器３０の電源投入時において、投光器２０の起動を確認した場合にのみ異常判断が許可されることとなる。受光側ＣＰＵ３５は、図７のようなフローチャートに基づいてこのような許可を行う機能を有し、許可手段の一例に相当している。 In this embodiment, as shown in S30 to S50, when the line synchronization method is adopted, abnormality determination is permitted only when the activation of the projector 20 is confirmed when the light receiver 30 is turned on. Become. The light-receiving side CPU 35 has a function of performing such permission based on a flowchart as shown in FIG. 7, and corresponds to an example of a permission unit.

以上のように、本実施形態の構成によれば、外部制御機器７０に検出信号を出力する場合、受光器３０から出力される信号を直接外部機器に入力させるのではなく、半導体リレーなどのスイッチング手段を介在させることも可能となり、ノイズ等に強い高精度な出力構成を実現できる構成となる。 As described above, according to the configuration of the present embodiment, when a detection signal is output to the external control device 70, the signal output from the light receiver 30 is not directly input to the external device, but switching such as a semiconductor relay is performed. It is also possible to intervene a means, and a high-accuracy output configuration that is resistant to noise and the like can be realized.

一方、受光器と外部機器との間にスイッチング手段を介在させる場合、本実施形態のようにそのスイッチング手段が正常に作動しているか否かを検出できるようにすると、検出信号の信頼性がより一層高まる。具体的には、投受光動作中にスイッチング手段が正常動作に応じて出力する正常動作信号を受光器に設けられた異常検出端子にて取得できるようにし、その正常動作信号に基づいて受光器側でスイッチング手段が正常であるか否かを判断できるようにしているため、高精度かつ異常検出可能な出力構成を複雑な構成を伴うことなく実現できる。 On the other hand, when the switching means is interposed between the light receiver and the external device, it is possible to detect whether or not the switching means is operating normally as in this embodiment, so that the reliability of the detection signal is further improved. Increased further. Specifically, the normal operation signal output by the switching means according to the normal operation during the light projecting / receiving operation can be acquired at the abnormality detection terminal provided in the light receiver, and the light receiver side is based on the normal operation signal. Therefore, it is possible to determine whether the switching means is normal or not, so that an output configuration capable of detecting an abnormality with high accuracy can be realized without a complicated configuration.

他方、利用者によっては、スイッチング手段を介在させずに用いたい場合もあるため、そのような場合にも好適に対応できる構成となっている。即ち、投受光動作中に正常動作信号として扱われる信号を、同期信号と対応させて出力する補助出力端子を投光器側に設けており、補助出力端子を異常検出端子に接続するだけで、正常動作信号として扱われる信号が投受光動作中に異常検出端子に入力されるようになるため、スイッチング手段を介在させなくても異常とならなくなり、スイッチング手段を介在させない使用を容易に実現できる。 On the other hand, depending on the user, there is a case where it is desired to use the switching means without any intervening means. In other words, an auxiliary output terminal is provided on the projector side to output a signal that is treated as a normal operation signal during the light projecting / receiving operation in correspondence with the synchronization signal, and normal operation is performed simply by connecting the auxiliary output terminal to the abnormality detection terminal. Since the signal treated as a signal is input to the abnormality detection terminal during the light projecting / receiving operation, it does not become abnormal even if the switching means is not interposed, and the use without the switching means can be easily realized.

また、受光器で正常動作信号を取得して異常判断を行う構成の場合、何ら措置を講じないと多光軸光電センサ全体として立ち上がっていない場合に不具合が生じてしまう。例えば、受光器を電源投入して立ち上げた場合において、他方の投光器では未だ電源投入されていない場合、受光器では異常監視が開始されるものの、投受光動作されるべきタイミングで投光器から投光動作がなされないため、スイッチング手段が動作することはなく、結果として投受光動作されるべきタイミングで正常動作信号が出力されないこととなる。従って、スイッチング手段に不具合がなくても受光器で異常判定されるという不具合が生じることとなる。しかしながら、本実施形態の構成では、投光器が電源投入されることを条件として異常判断を許可するようにしているため、このような不具合を効果的の防止できる。 Further, in the case of a configuration in which a normal operation signal is acquired by a light receiver and an abnormality is determined, a problem occurs when the entire multi-optical axis photoelectric sensor has not been started up unless any measures are taken. For example, when the receiver is turned on and started up, if the other projector is not turned on yet, the receiver will start monitoring the abnormality, but the projector will emit light at the timing at which light should be sent and received. Since the operation is not performed, the switching means does not operate, and as a result, the normal operation signal is not output at the timing when the light projecting / receiving operation is to be performed. Therefore, even if the switching means is not defective, there is a problem that an abnormality is determined by the light receiver. However, in the configuration of the present embodiment, the abnormality determination is permitted on condition that the projector is turned on, so that such a problem can be effectively prevented.

＜他の実施形態＞
本発明は上記記述及び図面によって説明した実施形態に限定されるものではなく、例えば次のような実施形態も本発明の技術的範囲に含まれ、さらに、下記以外にも要旨を逸脱しない範囲内で種々変更して実施することができる。 <Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention, and further, within the scope not departing from the gist of the invention other than the following. Various modifications can be made.

（１）上記実施形態では、各同期信号と同タイミングで出力される検出信号を例示したが、受光状態を反映した信号を同期信号と関連付けて出力するものであればこのような例に限られない。例えば、１スキャン周期において、いずれかの光軸で遮光があった場合（いずれかの光軸の受光量が所定の閾値以下の場合）にオフ信号を出力し、全ての光軸で遮光がない場合（全ての光軸の受光量が閾値を超えている場合）にオン信号を出力するような検出信号であってもよい。 (1) In the above embodiment, the detection signal output at the same timing as each synchronization signal has been exemplified. However, the detection signal is limited to such an example as long as the signal reflecting the light receiving state is output in association with the synchronization signal. Absent. For example, in one scan cycle, when any one of the optical axes is shielded (when the amount of light received by any one of the optical axes is equal to or less than a predetermined threshold), an off signal is output, and all the optical axes are not shielded. In such a case (a case where the received light amount of all the optical axes exceeds a threshold value), a detection signal that outputs an ON signal may be used.

（２）上記実施形態では、許可手段に相当する受光側ＣＰＵ３５は、全部の投光素子（投光手段）からの光を対応する各受光素子（受光手段）で受光した場合に図７の処理を終了させ、異常判断を許可する結果となっているが、予め設定される所定の投光素子（投光手段）からの光を対応する各受光素子（受光手段）で受光したか否かに基づいて投光器の起動を確認し、異常判断を許可するようにしてもよい。例えば、１スキャン周期において一番始めに投光動作する光軸の投光素子を所定の投光素子とし、この投光素子からの光を当該投光素子に対応する受光素子で受光した場合に投光器２０が起動したものとして図７の初期処理を終了させ、異常判断を許可するようにしてもよい。 (2) In the above embodiment, the light receiving side CPU 35 corresponding to the permission means receives the light from all the light projecting elements (light projecting means) by the corresponding light receiving elements (light receiving means). As a result, the abnormality determination is permitted, but whether or not light from a predetermined light projecting element (light projecting means) set in advance is received by each corresponding light receiving element (light receiving means) is determined. Based on this, the activation of the projector may be confirmed, and abnormality determination may be permitted. For example, when a light projecting element of the optical axis that performs the light projecting operation first in one scan cycle is a predetermined light projecting element, and light from this light projecting element is received by a light receiving element corresponding to the light projecting element The initial processing of FIG. 7 may be terminated as a result of the projector 20 being activated, and abnormality determination may be permitted.

（３）上記実施形態では、予め設定される１又は複数の投光手段（実施形態１では全投光手段）からの光を対応する各受光手段により受光した場合に投光器２０の起動を確認したものとして異常判断を許可しているが、予め設定される１又は複数の投光手段から予め設定される所定回数受光した場合に投光器２０の起動を確認したものとして図７の初期処理を終了させ、異常判断を許可するようにしてもよい。 (3) In the above embodiment, the activation of the projector 20 is confirmed when light from one or more preset light projecting means (all light projecting means in the first embodiment) is received by the corresponding light receiving means. Although the abnormality determination is permitted, the initial processing of FIG. 7 is terminated assuming that the projector 20 has been activated when light is received a predetermined number of times from one or more preset light projecting means. Alternatively, abnormality determination may be permitted.

実施形態１に係る多光軸光電センサの構成を概念的に例示する斜視図1 is a perspective view conceptually illustrating the configuration of a multi-optical axis photoelectric sensor according to Embodiment 1. FIG. 実施形態１の多光軸光電センサ及び周辺機器の電気的構成を概念的に例示する回路図1 is a circuit diagram conceptually illustrating the electrical configuration of a multi-optical axis photoelectric sensor and peripheral devices according to Embodiment 1. 同期信号、投光信号、受光動作信号、検出信号、正常動作信号、擬似正常動作信号の関係を例示するタイミングチャートTiming chart illustrating the relationship among synchronization signal, light projection signal, light reception operation signal, detection signal, normal operation signal, and pseudo normal operation signal Ａ接点スイッチＳＷ１が正常動作しない場合のタイミングチャートTiming chart when A contact switch SW1 does not operate normally リレーユニットを介さずに外部装置に出力する構成を概念的に例示する回路図The circuit diagram which illustrates conceptually the composition outputted to an external device without going through a relay unit 多光軸光電センサの要部外観を例示する概略図Schematic illustrating the main part of the multi-optical axis photoelectric sensor 実施形態１に用いられる受光器の電源投入時の初期処理を例示するフローチャート6 is a flowchart illustrating an initial process when the power of the optical receiver used in the first embodiment is turned on.

Explanation of symbols

１０…多光軸光電センサ
２０…投光器
２１ａ〜２１ｄ…投光素子
２３ａ〜２３ｄ…ＡＮＤ回路（投光制御手段）
２４…シフトレジスタ（投光制御手段）
２５…投光側ＣＰＵ（投光制御手段）
３０…受光器
３１ａ〜３１ｄ…受光素子
３３ａ〜３３ｄ…アナログスイッチ（受光制御手段）
３５…受光側ＣＰＵ（同期信号生成手段、受光制御手段、異常判断手段、報知手段、許可手段）
３７…シフトレジスタ（受光制御手段）
３８…表示部（報知手段）
４０…同期線
Ｌ１〜Ｌ４…光軸
Ｓａ…検出信号
Ｓｃ…正常動作信号
Ｓｅ…擬似正常動作信号（正常動作信号として扱われる信号）
Ｓｔ…同期信号
ＳＷ１…Ａ接点スイッチ（スイッチング手段）
ＳＷ２…Ｂ接点スイッチ（正常動作信号出力手段）
Ｐ１…外部出力端子
Ｐ２…異常検出端子
Ｐ５…補助出力端子 DESCRIPTION OF SYMBOLS 10 ... Multi-optical axis photoelectric sensor 20 ... Light projector 21a-21d ... Light projection element 23a-23d ... AND circuit (light projection control means)
24. Shift register (light projection control means)
25 ... Projection side CPU (projection control means)
30... Light receivers 31 a to 31 d... Light receiving elements 33 a to 33 d... Analog switch (light reception control means)
35... Light receiving side CPU (synchronization signal generating means, light receiving control means, abnormality determination means, notification means, permission means)
37. Shift register (light receiving control means)
38 ... Display section (notification means)
40 ... Synchronization line L1-L4 ... Optical axis Sa ... Detection signal Sc ... Normal operation signal Se ... Pseudo normal operation signal (signal treated as normal operation signal)
St ... Sync signal SW1 ... A contact switch (switching means)
SW2 ... B contact switch (normal operation signal output means)
P1 ... External output terminal P2 ... Abnormality detection terminal P5 ... Auxiliary output terminal

Claims

A projector having a plurality of projector elements;
A light receiver including a plurality of light receiving elements arranged to form an optical axis with each light projecting element;
A synchronization line connecting the projector and the light receiver;
Synchronization signal generating means for generating a synchronization signal transmitted from the light receiver to the projector via the synchronization line;
Projection control means for controlling the projection timing of each projection element based on the synchronization signal transmitted through the synchronization line;
A light receiving control means for performing a light receiving operation in synchronization with a light projecting timing of the light projecting element that forms the optical axis in opposition to each light receiving element based on the synchronization signal;
An external output terminal that is configured to output a detection signal based on a light receiving state of each light receiving element by the light receiving control means to the outside and to which a switching means that performs a switching operation corresponding to the detection signal can be connected;
An abnormality detection terminal to which a normal operation signal output means for outputting the normal operation signal corresponding to the detection signal is connectable when the switching means operates normally according to the detection signal;
An abnormality determination means for determining an abnormality of the switching means based on the synchronization signal and the normal operation signal input to the abnormality detection terminal;
An informing means for informing when an abnormality is determined by the abnormality determining means;
An auxiliary output terminal that, when electrically connected to the abnormality detection terminal, outputs a signal treated as the normal operation signal by the abnormality determination means to the abnormality detection terminal in association with the detection signal;
Permission means for permitting the abnormality determination by the abnormality determination means based on confirming the activation of the projector at the time of turning on the light receiver;
A multi-optical axis photoelectric sensor comprising:

2. The multi-optical axis photoelectric sensor according to claim 1, wherein the auxiliary output terminal outputs an on / off signal linked to the detection signal when the projector is powered on. 3.

The said permission means confirms starting of the said light projector based on whether the light from the predetermined said light projection means set in advance was received by each corresponding light reception means. Item 3. The multi-optical axis photoelectric sensor according to Item 2.

The multi-light according to claim 3, wherein the permission unit confirms activation of the projector based on whether or not the light from all the light projecting units is received by the corresponding light receiving units. Axis photoelectric sensor.

The permission unit confirms the activation of the projector based on whether or not the light from one or a plurality of the light projecting units set in advance is received by the corresponding light receiving units a predetermined number of times. The multi-optical axis photoelectric sensor according to claim 3 or 4, wherein:

A light receiving element of a light receiver provided with a synchronization signal generating means for generating a synchronization signal, and a plurality of light projecting elements arranged so as to constitute an optical axis, respectively, and the light projecting timing of each light projecting element to the synchronization signal A projector having a projector control means for controlling based on the projector;
A light receiving control means for causing the plurality of light receiving elements to receive light in synchronization with the light projecting timing of the light projecting elements that form the optical axis facing each light receiving element based on the synchronization signal; and An external output terminal configured to output a detection signal based on a light receiving state of each light receiving element to the outside, to which a switching unit that performs a switching operation corresponding to the detection signal can be connected, and the switching unit to the detection signal In response to the normal operation, the normal operation signal output means for outputting the normal operation signal corresponding to the detection signal is connectable to the abnormality detection terminal, the synchronization signal, and the abnormality detection terminal input to the abnormality detection terminal An abnormality determining means for determining an abnormality of the switching means based on a normal operation signal, and a notification when an abnormality is determined by the abnormality determining means. Connected via a synchronization line to the light receiver comprising a notification means and a permission means for permitting the abnormality determination by the abnormality determination means based on confirming the activation of the projector when the light receiver is turned on Configured
An auxiliary output terminal that outputs a signal that is treated as the normal operation signal by the abnormality determination means to the abnormality detection terminal in association with the detection signal when electrically connected to the abnormality detection terminal; A projector for a multi-optical axis photoelectric sensor.

A projector including a synchronization signal generating unit configured to generate a synchronization signal, a projector including a plurality of light projecting elements, and a light projecting control unit configured to control a light projecting timing of each light projecting element based on the synchronization signal; A receiver connected via
A plurality of light receiving elements arranged to form an optical axis with each light projecting element;
A light receiving control means for performing a light receiving operation in synchronization with a light projecting timing of the light projecting element that forms the optical axis in opposition to each of the light receiving elements based on the synchronization signal;
An external output terminal that is configured to output a detection signal based on a light receiving state of each light receiving element by the light receiving control means to the outside and to which a switching means that performs a switching operation corresponding to the detection signal can be connected;
An abnormality detection terminal to which a normal operation signal output means for outputting a normal operation signal corresponding to the detection signal when the switching means operates normally in response to the detection signal;
An abnormality determination means for determining an abnormality of the switching means based on the synchronization signal and the normal operation signal input to the abnormality detection terminal;
An informing means for informing when an abnormality is determined by the abnormality determining means;
With
The abnormality detection terminal is connectable to an auxiliary output terminal provided in the projector so as to output a signal treated as the normal operation signal by the abnormality determination means in association with the detection signal,
The light receiver of the multi-optical axis photoelectric sensor further comprising permission means for permitting an abnormality determination by the abnormality determination means based on confirming the start of the projector when the light receiver is turned on.